José Raúl Capablanca was one of the most divinely gifted chess players the world has seen. He had an effortless style and rarely lost. He was particularly effective at endgames – the mark of a grandmaster. He became world champion in 1921, the year in which he wrote Chess Fundamentals, which is one of the finest brief chess books ever written.

The book is not designed for beginners but for those who want a refresh on the fundamental principles of practical play. A large part of the book is about endings. The following position is left to the reader as an exercise. The position became notorious at one point because one edition of the book had a mistranslation which suggested that white would only draw. However, the position is a win for white.

Chess Fundamentals
Pawn Endings

White to play and win.

There are three relevant candidate moves for White.

1. g5? only draws after 1..g6 because black can keep his king opposed to white’s king thus preventing the advance of pawn to f5.

1. f5 is winning but not exactly straightforward. “The best answer is 1…g6 (The student should work this out.“) This is the tricky position that fooled one translator. What happens after 2.fxg? The winning technique is set out below.

1. Ke4 is the move recommended by Capa. He goes on to describe the winning technique after which he comments:

This ending, apparently so simple, should show the student the enornous difficulties to be surmounted, even when there are hardly any pieces left, when playing against an adversary who knows how to use the resources at his disposal, and it should also show the student the necessity of paying strict attention to these elementary things which form the bais of true mastership in chess.

See below for the winning techniques.

The importance of this ending was underlined in a few years later at the Third Chess Olympiad in Hamburg in 1930. The British Chess Champion of 1929, Mir Sultan Khan, formerly of Kingston chess club (history), lost to Karl Ruben. Ruben was a very fine player and had helped Denmark to the silver medal in the previous Olympiad of 1927. Both Ruben and Sultan Khan were in competitive chess for a narrow time window around 1930 and then retired from active play.

Karl Ruben v Mir Sultan Khan
Chess Olympiad Hamburg 1930

Black to play cannot save the game.

White forces the black king away from the promotion square.

Sultan Khan saw that his only chance was to trick Ruben into stalemate. However, Ruben underpromoted to a rook and Sultan Khan resigned. A promotion to a minor piece would have been even more emphatic that Sultan Khan should have resigned. Ruben could also have sacrificed his f-pawn as in the Capablanca variations above.